The field of the invention is map holding and displaying apparatus, and the invention relates more particularly to maps which are held on a spring roller of the type commonly used in classrooms. A basic design of map holder which has been on the market for many years is shown in U.S. Pat. No. 1,786,038. This utilizes a map rail which supports several map rail hooks which, in turn, support a map.
Maps are most commonly stored on a spring roller so that they may be easily retracted when not in use. Since many classroom maps are quite large and heavy, it occasionally happens that when the map is released from its unrolled position, the spring in the spring roller causes it to retract rapidly if not restrained by the instructor. The inertia caused by the retracting map can actually lift the channel which is held by the map hooks and occasionally the channel becomes unhooked and can fall to the floor causing possible injury.
Various design improvements have been made over the years including an upper notch on the map rail hook which often is sufficient to restrain the map. Occasionally, however, maps of the present design do fall from the map hooks.